<i>Pinus radiata</i> blocks treated with copper-chrome-arsenate formulation Tanalith NCA were sectioned by four different methods for x-ray analysis using transmission electron microscopy. Sections of unembedded wood cut with a dry glass knife and mounted on grids without contact with liquid gave minimum redistribution or loss of the preservative elements from the tracheid cell walls; results were reproducible and this procedure was considered a reliable method of preparation. The other methods (unembedded sections mounted using water, and oven dried or ethanol dehydrated sections embedded in resin) caused losses or redistribution of copper, chromium, and arsenic from the tracheid S2 layer. These changes varied with element and with copper-chrome-arsenate solution strength. These methods were therefore not recommended. -- AATA